Display control apparatus, head mounted display, and display control method

ABSTRACT

There is provided a display control apparatus capable of displaying a high-quality image while inhibiting a load at the time of displaying the image in front of a user. There is provided a display control apparatus including a signal processing unit that performs signal processing in which a first mode and a second mode are switchable at a first region in a screen and a region other than the first region in the screen, display being performed at a first resolution in the first mode, display being performed at a second resolution in the second mode, in which the signal processing unit performs display while reducing a resolution in the second mode toward an outer periphery of the screen.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase of International PatentApplication No. PCT/JP2018/032533 filed on Sep. 3, 2018, which claimspriority benefit of Japanese Patent Application No. JP 2017-204296 filedin the Japan Patent Office on Oct. 23, 2017. Each of theabove-referenced applications is hereby incorporated herein by referencein its entirety.

TECHNICAL FIELD

The present disclosure relates to a display control apparatus, a headmounted display, a display control method, and a computer program.

BACKGROUND ART

In a small display represented by a micro display, possible applicationsare used through a lens at a place very close to human eyes, such as anelectronic viewfinder (EVF) and a head mounted display (HMD). Forexample, Patent Document 1 and the like disclose a head mounted display.

CITATION LIST Patent Document

Patent Document 1: Japanese Patent Application Laid-Open No. 2016-153899

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

A small display used for a head mounted display is required to displayhigh-definition content. In contrast, display of high-definition contentincreases a load at the time of display processing.

Then, in the disclosure, there is proposed a new and improved displaycontrol apparatus, head mounted display, display control method, andcomputer program capable of displaying a high-quality image whileinhibiting a load at the time of displaying the image in front of auser.

Solutions to Problems

According to the disclosure, there is provided a display controlapparatus including a signal processing unit that performs signalprocessing in which a first mode and a second mode are switchable at afirst region in a screen and a region other than the first region in thescreen, display being performed in the screen at a first resolution inthe first mode, display being performed in the screen at a secondresolution in the second mode.

Furthermore, according to the disclosure, a head mounted displayincluding the above-described display control apparatus is provided.

Furthermore, according to the disclosure, there is provided a displaycontrol method including a processor performing signal processing inwhich a first mode and a second mode are switchable at a first region ina screen and a region other than the first region in the screen, displaybeing performed in the screen at a first resolution in the first mode,display being performed in the screen at a second resolution in thesecond mode.

Furthermore, according to the disclosure, there is provided a computerprogram causing a computer to perform signal processing in which a firstmode and a second mode are switchable at a first region in a screen anda region other than the first region in the screen, display beingperformed in the screen at a first resolution in the first mode, displaybeing performed in the screen at a second resolution in the second mode.

Effects of the Invention

As described above, according to the disclosure, there can be proposed anew and improved display control apparatus, head mounted display,display control method, and computer program capable of displaying ahigh-quality image while inhibiting a load at the time of displaying theimage in front of a user.

Note that the above-described effect is not necessarily limitative, and,along with or in place of the above-described effect, any of the effectsillustrated in the present specification, or other effects that can begrasped from the specification may be exhibited.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is an explanatory view for illustrating an FOV.

FIG. 2 is an explanatory view outlining a display apparatus according toan embodiment of the disclosure.

FIG. 3 is an explanatory view illustrating a central view-field regionand a peripheral view-field region.

FIG. 4 is an explanatory view illustrating the relation between aviewing angle and the size of a video (virtual image displayed on avirtual image plane).

FIG. 5 is an explanatory graph illustrating the relation between aviewing angle and the size of a video (virtual image displayed on avirtual image plane).

FIG. 6 is an explanatory view illustrating the pixel number of adisplay.

FIG. 7 is an explanatory view illustrating a configuration example of adisplay system according to the embodiment of the disclosure.

FIG. 8 is an explanatory view illustrating a configuration example of agate driver unit 102.

FIG. 9 is an explanatory view illustrating a configuration example of adata driver unit 103.

FIG. 10 is an explanatory view for illustrating the processing ofgenerating a pixel size control signal performed by a signal processingunit 104.

FIG. 11 is an explanatory graph illustrating the relation between aviewing angle equal to or larger than a central view field and a pixelmagnification.

FIG. 12A is an explanatory table illustrating the relation between aviewing angle and a pixel magnification.

FIG. 12B is an explanatory table illustrating the relation between aviewing angle and a pixel magnification.

FIG. 13 is an explanatory view illustrating the operation of the signalprocessing unit 104.

FIG. 14 is an explanatory view illustrating a display grid for eachviewing angle.

FIG. 15A is an explanatory view illustrating values stored in a look-uptable of a display rate to a viewing angle.

FIG. 15B is an explanatory view illustrating values stored in thelook-up table of a display rate to a viewing angle.

FIG. 16 is an explanatory view illustrating the operation of the signalprocessing unit 104.

FIG. 17A is an explanatory view illustrating values, stored in thelook-up table, of the pixel number to a viewing angle.

FIG. 17B is an explanatory view illustrating values, stored in thelook-up table, of the pixel number to a viewing angle.

FIG. 18 is an explanatory view illustrating the operation of the signalprocessing unit 104.

FIG. 19A is an explanatory view illustrating values, stored in thelook-up table, of a magnification to a pixel.

FIG. 19B is an explanatory view illustrating values, stored in thelook-up table, of a magnification to a pixel.

FIG. 20 is an explanatory view illustrating an ID of a selection gateactually generated by the signal processing unit 104.

FIG. 21A is an explanatory table illustrating a selection gate ID foreach viewing angle and a value obtained by representing each selectiongate ID at 12 bits.

FIG. 21B is an explanatory table illustrating the selection gate ID foreach viewing angle and the value obtained by representing each selectiongate ID at 12 bits.

FIG. 22 is an explanatory view illustrating output timing for each row.

FIG. 23 is an explanatory view illustrating an example of a circuitconfiguration of the selection unit 201.

FIG. 24 is an explanatory view illustrating the operation of theselection unit 201.

FIG. 25 is an explanatory view illustrating the operation in a casewhere a control signal incremented by one bit is input to the selectionunit 201.

FIG. 26 is an explanatory view illustrating configuration examples of aDAC unit 301, an AMP unit 302, and a selection unit 303.

FIG. 27 is an explanatory view illustrating the operation of theselection unit 303.

FIG. 28 is an explanatory view illustrating the operation in a casewhere a control signal incremented by one bit is input to the selectionunit 303.

FIG. 29 is an explanatory view illustrating a configuration example ofthe display system according to the embodiment.

FIG. 30 is an explanatory view illustrating input/output of image data.

FIG. 31 is an explanatory view illustrating the driving of the gatedriver unit 102.

FIG. 32 is an explanatory view illustrating the driving of the datadriver unit 103.

MODE FOR CARRYING OUT THE INVENTION

A preferred embodiment of the disclosure will be described in detailbelow with reference to the accompanying drawings. Note that, in thespecification and the drawings, components having substantially the samefunctional configuration will be assigned the same signs, and redundantdescription will be omitted.

Note that the description will be given in the following order.

1. Embodiment of Disclosure

1.1. Outline

1.2. Configuration Example and Operation Example

2. Conclusion

1. EMBODIMENT OF DISCLOSURE 1.1. Outline

Prior to describing an embodiment of the disclosure in detail, first,the embodiment of the disclosure will be outlined.

Substrates for achieving a panel in a spontaneous light emitting displayof current-driven type represented by an organic EL display are roughlyclassified into amorphous substrates and Si substrates. The amorphoussubstrates are represented by LIPS and an oxide. The Si substrates arerepresented by silicon (Si)

single crystal. The advantage of the amorphous substrates is that theamorphous substrates can be used for a large format display. Theadvantage of the Si substrates is that the Si substrates can achieve asmall and high-definition display. Possible applications are alsoclassified on the basis of characteristics. The amorphous substrates areapplied to large TVs and medium-sized displays for a smartphone. The Sisubstrates are applied to small displays such as electronic viewfindersand head mounted displays.

In a small display represented by a micro display, possible applicationsare used through a lens at a place very close to human eyes, such as anelectronic viewfinder (EVF) and a head mounted display (HMD). Such aseries of applications is called a near-to-eye (NTE) application. An NTEapplication of an EVF and that of an HMD differ in an optical system.The EVF shows a video by bringing a real image magnified mainly by alens into eyes, while the HMD reproduces a virtual image magnified manytimes on the retina. For example, a micro display of an HMD used forputting a 100-inch display 20 m ahead has a size of approximately oneinch, which shows very high magnification.

In recent years, virtual reality (VR) has been actively developed. TheVR is an application that provides a video completely covering the fieldof view of a user at the time when the user wears a head mounteddisplay, and gives a sense of immersion. The field of view (FOV) is avery important parameter for giving the sense of immersion. In a casewhere the FOV exceeds 100 degrees, a video can cover the entire field ofview. FIG. 1 is an explanatory view for illustrating the FOV. Forexample, in a case where the horizontal and vertical FOVs at one meterahead from eyes of a user are both 100 degrees, the magnified displaysize exceeds 130 inches. In a case where the display size is extended toapproximately 130 inches, a VR apparatus using a display with lowresolution expresses a video with no sense of resolution. For thisreason, a display used in a VR apparatus requires a resolution exceeding4 k×4 k with a field of view of 8 k×8 k to 16 k×16 k. Here, since a VRdisplay needs a high FOV both horizontally and vertically, a 1:1 aspectis strongly required.

A considerably large system is necessary for driving the above-describeddisplay with a resolution exceeding 4 k×4 k for VR. For example,approximately twice the bit rate of a drive system of a resolution of 4k×2 k and a refresh rate of 60 fps is necessary for driving a displaywith a resolution exceeding 4 k×4 k. Furthermore, VR requires high-speeddriving of 120 fps or more, so that the bit rate is further doubled.That is, approximately four times the bit rate of the drive system of aresolution of 4 k×2 k and a refresh rate of 60 fps is necessary. In acase where the resolution is further raised to 8 k×8 k, approximately 16times the bit rate of the drive system of a resolution of 4 k×2 k and arefresh rate of 60 fps is necessary.

In addition to the bit rate, unlike a purpose of normal direct vision,it is necessary in VR to feed back a result of tracking (head tracking)of the motion of a head mounted display worn on a head to the system andchange video data. Therefore, it is necessary to constantly performsignal processing on large amounts of video data. Large amounts ofsystem costs are necessary for performing signal processing on data of16 times or more of 4 k×2 k at high speed, and such signal processing isimpractical. Therefore, a VR display capable of expressing ahigh-definition video with low load is required.

In view of the above-described points, the present discloser hasconducted intensive studies on a technique capable of displaying ahigh-quality image while inhibiting a load at the time of displaying theimage in front of a user. As a result, as described below, the presentdiscloser has devised a technique capable of displaying a high-qualityimage while inhibiting a load at the time of displaying the image infront of a user.

The embodiment of the disclosure has been outlined above. Subsequently,the embodiment of the disclosure will be described in detail.

1.2. Configuration Example and Operation Example

In the present embodiment, a display apparatus capable of expressinghigh resolution with low load is provided. Specifically, the embodimentis directed to a display capable of displaying different pixel sizes inthe same panel. FIG. 2 is an explanatory view outlining a displayapparatus according to the embodiment of the disclosure, and illustratesa display capable of displaying different pixel sizes in the same panel.The reason for this will be described.

The field of view of a person has a central view-field region and aperipheral view-field region. FIG. 3 is an explanatory view illustratingthe central view-field region and the peripheral view-field region. Thecentral view-field region is a region which a person focuses on, and theperson can accurately grasp colors and shapes in the region. The centralview-field region has a high resolution that can be recognized by ahuman. In contrast, the peripheral view-field region is placed outsidethe central view-field region. In the peripheral view-field region,motion in a wide range and a position are grasped. The peripheralview-field region has little connection with a photoreceptor cell, andlow resolution that can be recognized.

Generally, the FOV of the central view field is approximately 40degrees, and the rest can be considered as the peripheral view field.That is, a high-resolution video with high ppi is displayed only in thecentral view-field region where a human can recognize high resolution(i.e., central view-field region has a small and fine pixel size). Alow-resolution video with low ppi is displayed in the peripheral viewfield with low resolution (i.e., large and coarse pixel size). Suchdisplay enables a person to recognize a video as a very natural andhigh-resolution video.

FIG. 4 is an explanatory view illustrating the relation between aviewing angle and the size of a video (virtual image displayed on avirtual image plane). Furthermore, FIG. 5 is an explanatory graphillustrating the relation between a viewing angle and the size of avideo (virtual image displayed on a virtual image plane). If a displayedregion, a viewing distance, and a viewing angle are defined as x, d, andα, respectively, x=d*tan(α) is defined. In a case of a normal flatdisplay, a viewing angle and a display area size have the relation of afunction of tangent. For example, if the maximum FOV and the centralview-field region are defined as 100 degrees (50 degrees on one side)and 40 degrees (20 degrees on one side), respectively, the centralview-field region corresponds to approximately 30% of the entire region.

Suppose a micro display has the specifications of a size of one inch, anaspect of 1:1, and the maximum FOV of 100 degrees. FIG. 6 is anexplanatory view illustrating the total pixel number in a case where thecentral view-field region with an FOV of 40 degrees and the peripheralview-field region of 100 degrees are displayed in pixel sizes of 4 k×4 kequivalent (approximately 4.2 um) and 2 k×2 k equivalent (approximately8.3 um), respectively, in a display with such specifications. In thedisplay with the above-described specifications, the total pixel numberis (1−0.09)*(2 k×2 k)+0.09 (4 k×4 k)=approximately 5 million.

In contrast, in a case where all regions are driven at a uniformresolution of 4 k×4 k, the pixel number is approximately 16 million.Consequently, if the central view-field region and the peripheralview-field region of 100 degrees are displayed in pixel sizes of 4 k×4 kequivalent (approximately 4.2 um) and 2 k×2 k equivalent (approximately8.3 um), respectively, the pixel number can actually be compressed toapproximately 70% compared to that in a case where all regions aredisplayed at a uniform resolution of 4 k×4 k. A system of 2.5 k×2.5 k orless can drive the display panel, and inevitably a 4 k×2 k system, whichis currently becoming mainstream, can sufficiently drive the displaypanel.

Consequently, the display system according to the embodiment of thedisclosure prepares at least two display modes having different displayresolutions. Then, the display system according to the embodiment of thedisclosure performs display in a display mode (first display mode) fordisplaying a high-resolution image in a region in an image, for example,the central view-field region. The display system performs display in adisplay mode (second display mode) with a resolution lower than that ofthe first display mode in another region, for example, the peripheralview-field region. The display system according to the embodiment of thedisclosure prepares at least two display modes having such differentdisplay resolutions, and performs display in display modes different inaccordance with regions, so that the display system can display ahigh-quality image while inhibiting a load at the time of displaying theimage in front of a user. Note that, although, in the embodiment, thefirst display mode has a resolution higher than that of the seconddisplay mode, the disclosure is not limited to the example. For example,the first and second display modes may have the same resolution.

FIG. 7 is an explanatory view illustrating a configuration example ofthe display system according to the embodiment of the disclosure. Anobject of the display system in FIG. 7 is to display an image or thelike in front of a user. Such a display system includes a display systemused for, for example, a head mounted display and the like and a displaysystem used for a head mounted display and the like for allowing a userto experience virtual reality (VR) and augmented reality (AR).

As illustrated in FIG. 7, the display system according to the embodimentof the disclosure includes a panel unit 101, a gate driver unit 102, adata driver unit 103, and a signal processing unit 104. In the panelunit 101, pixels 100, which express the central view-field region andhave an original pixel size, are spread over the entire region. The gatedriver unit 102 drives a vertical scanning line. The data driver unit103 gives a signal in a horizontal direction. The signal processing unit104 determines the size of a pixel to be displayed.

The panel unit 101 is driven by an active matrix driving method. Allpixels of the panel unit 101 are connected to the gate driver unit 102and the data driver unit 103.

The signal processing unit 104 includes, for example, any processor, forexample, a graphic processor. The signal processing unit 104 gives anycontrol signal for causing the gate driver unit 102 and the data driverunit 103 to drive the panel unit 101. Particularly in the embodiment, asdescribed above, the signal processing unit 104 processes a signalprocessing for performing display in a display mode (first display mode)for displaying a high-resolution image in a region of the panel unit101, for example, the central view-field region, and for performingdisplay in a display mode (second display mode) with a resolution lowerthan that of the first display mode in another region of the panel unit101, for example, the peripheral view-field region.

FIG. 8 is an explanatory view illustrating a configuration example ofthe gate driver unit 102. As illustrated in FIG. 8, the gate driver unit102 includes a scanner unit 200, a selection unit 201, and a buffer unit202. The scanner unit 200 sequentially transfers a vertical writingsignal. The selection unit 201 selects any signal from sequentiallytransferred vertical writing signal. The buffer unit 202 performsimpedance conversion from the writing signal to a signal to be writtento a pixel. The scanner unit 200 transmits a signal to the selectionunit 201 through an output node 203.

FIG. 9 is an explanatory view illustrating a configuration example ofthe data driver unit 103. As illustrated in FIG. 9, the data driver unit103 includes a scanner unit 300, a DAC unit 301, an AMP unit 302, and aselection unit 303. The scanner unit 300 transfers data to be writtenwithin a horizontal period. The DAC unit 301 converts a digital signalto an analog signal. The AMP unit 302 writes an analog voltage to apixel. The selection unit 303 selects a data line to be written.

The display system according to the embodiment of the disclosure canoptionally change a pixel size in the same panel by inputting anycontrol signal from the signal processing unit 104 to each of theselection unit 201 in FIG. 8 and the selection unit 303 in FIG. 9 andsimultaneously driving a plurality of lines of a gate signal line and adata signal line.

Here, processing of generating a pixel size control signal performed bythe signal processing unit 104 will be described. FIG. 10 is anexplanatory view for illustrating the processing of generating a pixelsize control signal performed by the signal processing unit 104. Thesignal processing unit 104 first determines an area to be displayed inan original pixel size. The original pixel size is the size of the pixel100 in FIG. 7, that is, the minimum size of pixels spread over theentire panel unit 101. Furthermore, the display system according to theembodiment has an aspect of 1:1, and can perform display up to verticaland horizontal viewing angles of F0. Furthermore, for simplicity ofdescription, F0=100° is assumed.

In determining an area to be displayed in the original pixel size, thesignal processing unit 104 determines a pixel magnification from thedisplay origin (0,0) in FIG. 10 to vertical and horizontal viewingangles. The signal processing unit 104 first determines a centralviewing angle f. The range of f can be set from 0° to F0. Normally, thecentral viewing angle is approximately 40°, and thus the signalprocessing unit 104 sets the central viewing angle at 40° here.

Next, the signal processing unit 104 sets display so that the pixel sizeis increased toward the outer periphery. Although various methods ofsetting are conceivable, in the embodiment, a method of approximation byusing a function is adopted. For example, in the embodiment, a casewhere a pixel size is set by using a quadratic function is considered.Furthermore, the pixel size at the outermost periphery is set to m. Thepixel size m means that the vertical and horizontal lengths aredisplayed to be m times larger than those of the original pixel. Forexample, if m=4 is set, the length of one side is quadrupled, so thatthe pixel size is increased by sixteen times.

The outermost periphery here means a region at the viewing angle F0(=100°). The signal processing unit 104 interpolates the viewing anglefrom f to F0 by using a quadratic function. If y is the magnification ofa pixel size and x is a viewing angle equal to or larger than thecentral view field, in a case of performing fitting with y=ax{circumflexover ( )}2+bx+c, the fitting curve of a magnification can be obtained bysolving m=a*((F0−f)/2){circumflex over ( )}2+b (F0−f)/2+c. Suppose m=4,F0=100, and f=40, y=2e−3*x{circumflex over ( )}2+4e−2*x+1 holds.

Actually, the pixel size can have only an integer value. Consequently,the magnification x in each view-field region has a discrete value. Thesignal processing unit 104 performs the interpolation processing in thevertical and horizontal directions to create a two-dimensional matrix ofa pixel size and coordinates.

FIG. 11 is an explanatory graph illustrating the relation between theviewing angle equal to or larger than the central view field and thepixel magnification. FIGS. 12A and 12B are explanatory tablesillustrating the relation between a viewing angle and a pixelmagnification. In the example, the original pixel size is used in aviewing angle region within 56° (±28°) from the center, and themagnification of the pixel size is one time. The viewing angle regionlarger than 56° and equal to or less than 78° has one side whose lengthis doubled, the pixel size is quadrupled. Furthermore, the viewing angleregion larger than 78° and equal to or less than 92° has one side whoselength is tripled, the pixel size is increased by nine times. Moreover,the viewing angle region larger than 92° and equal to or less than 100°has one side whose length is quadrupled, the pixel size is increased bysixteen times. The signal processing unit 104 can determine themagnification of a pixel size to a viewing angle by performing suchprocessing.

Next, the signal processing unit 104 generates the number ofsimultaneously driven lines of the gate signal line from the gate driverunit 102 to the panel unit 101 and the data signal line from the datadriver unit 103 to the panel unit 101.

First, the signal processing unit 104 generates a display grid for eachviewing angle. FIG. 13 is an explanatory view illustrating the operationof the signal processing unit 104. The signal processing unit 104generates the display grid for each viewing angle on the basis of theviewing angle in increments of one degree (Step S101). The generateddisplay grid for each viewing angle is stored in a look-up table (LUT)of a display rate to a viewing angle.

FIG. 14 is an explanatory view illustrating a display grid for eachviewing angle. β, x, x₁, and k are defined as a viewing angle, a displayregion of any viewing angle, a display region of a viewing angle of onedegree, and the rate of the display region to an area of one degree,respectively. The signal processing unit 104 generates an LUT thatstores the value of k in accordance with each viewing angle. The valueof k is obtained by the following expression. x=d*tan(β), x₁=d*tan(1),and k=x/x₁ FIGS. 15A and 15B are explanatory views illustrating values,determined by the above expression, stored in the look-up table of adisplay rate to a viewing angle.

For example, in a case of β=10, the value of k is approximately 10,which is approximately ten times the value of k in a case of β=1. Thatis, in a case of β=10, a region approximately 10 times as large as thatin a case of β=1 is required. In a case of β=40, the value of k isapproximately 48, which is approximately 48 times the value of k in acase of β=1. In a case of β=40, a region approximately 48 times as largeas that in a case of β=1 is required. That is, it can be seen that adisplay displaying area for expressing each viewing angle is not linearbut has any reach.

Next, the signal processing unit 104 generates the pixel number for theviewing angle (in increments of one degree). FIG. 16 is an explanatoryview illustrating the operation of the signal processing unit 104. Thesignal processing unit 104 generates a pixel number p by using a pixelnumber (p₀) and a maximum viewing angle (x_(m)) as input values (StepS102). The pixel number p is given from the expressions k_(m)=x_(m)/x₁and p=p₀*k/k_(m). The character p corresponds to the viewing angle (inincrements of one degree). The signal processing unit 104 creates an LUTthat stores the generated pixel number p in accordance with each viewingangle. Here, k_(m) is the rate of the display region at the time of themaximum viewing angle, and p is the pixel number in accordance withviewing angle (in increments of one degree). FIGS. 17A and 17B areexplanatory views illustrating values of the pixel number to the viewingangle. The values are determined in the above expression, and stored inthe look-up table.

For example, the case of the original pixel number of 4000×4000 and themaximum viewing angle of 100 degrees will be considered as the pixelnumber. Half the horizontal resolution is input as a pixel number p₀ ofan input value, and thus p₀=2000 holds. Furthermore, 50 degrees, whichis half the maximum viewing angle, are input as an input value. A valueof k_(m)=x_(m)/x₁=x(50)/x₁=approximately 68 is calculated from the LUT.As a result, the pixel number corresponding to each viewing angle isobtained as illustrated in FIGS. 17A and 17B. For example, it can beseen that a viewing angle of 20 to 21 degrees is expressed by 611 to 644(pixel number 33 pixels).

Next, the signal processing unit 104 generates a magnification for eachpixel. FIG. 18 is an explanatory view illustrating the operation of thesignal processing unit 104. The signal processing unit 104 creates anLUT in which a pixel magnification value for each viewing angle ispreliminarily stored. Consequently, the signal processing unit 104generates a look-up table corresponding to the look-up table of thepixel number in FIGS. 17A and 17B (Step S103). FIGS. 19A and 19B areexplanatory views illustrating values, stored in the look-up table, of amagnification to a pixel.

Referring to the look-up tables in FIGS. 19A and 19B, for example,pixels 0 to 892 has a magnification of one, and original pixels aredisplayed for the pixels. Pixels 893 to 1359 has a magnification of two,and the pixels are displayed in four times the size of the originalpixel. The look-up table is the final output result of the signalprocessing unit 104, and determines the number of simultaneously drivenlines of a gate and data. For example, if m=4, four lines aresimultaneously driven. Then, a simultaneously driven line number arrayof each gate and a signal line is created from each gate, a signal line,and an array of m.

The signal processing unit 104 transfers the generated control signal ofthe simultaneously driven line number to the gate driver unit 102 andthe data driver unit 103. FIG. 20 is an explanatory view illustrating anID of a selection gate actually generated by the signal processing unit104. Furthermore, FIGS. 21A and 21B are explanatory tables illustratinga selection gate ID for each viewing angle and a value obtained byrepresenting each selection gate ID at 12 bits. In the example in FIG.20, change of m=2, 3, and 4 occurs at magnification breakpoint pixelspi=930, 1408, and 1800, respectively. Selection data of each gate iscalculated by changing the inclination of increment in accordance withthe breakpoint.

The scanner unit 200 inside the gate driver unit 102 is a scannercircuit including a flip-flop, and performs transfer all the verticalpixel number per 1 H (horizontal cycle). Assuming that the resolutionobtained by spreading the original pixel sizes over the entire surfaceis equivalent to 4 k×4 k, the vertical pixel number is approximately4000, and 4000 output signals are output from the scanner unit 200. Thetiming of each output is shifted every 1 H, and the timing of 4000thline is delayed by 4000 H from that of the first line. FIG. 22 is anexplanatory view illustrating output timing for each row in a case wherethe vertical pixel number is approximately 4000. The selection unit 201selects any output from the 4000 output signals.

The number of 4000 can be expressed by at least 12 bits. This is because12 bits can express 4096 values from 0 to 4095. Consequently, theselection unit 201 operates on the basis of a 12-bit signal output froma 12-bit DAC. That is, the selection unit 201 includes 12 stages oftransistors. FIG. 23 is an explanatory view illustrating an example of acircuit configuration of the selection unit 201. In the embodiment, theselection unit 201 includes 12 stages of transistors for each row.Needless to say, the number of transistors used in the selection unit201 can be reduced from the 12 stages by combination with a logiccircuit.

The selection unit 201 selects timing of input to the buffer unit 202.For example, in a case where the control signal input to the selectionunit 201 of all lines is [000000000000], all the lines select the timingof the 1st H, and thus all pixels are simultaneously driven. FIG. 24 isan explanatory view illustrating the operation of the selection unit 201in a case where the control signal is [000000000000].

Furthermore, in a case where a control signal incremented by one bitfrom [000000000000] to [111111111111] is input to the selection unit201, the panel unit 101 is driven in a normal active matrix driving inwhich scanning is performed every 1 H. FIG. 25 is an explanatory viewillustrating the operation in a case where a control signal incrementedby one bit is input to the selection unit 201. If a control signalincremented by one bit is input to the selection unit 201 in this way,the panel unit 101 is driven in the active matrix driving.

The scanner unit 300 inside the data driver unit 103 transfers digitaldata to be written to each pixel while transferring a clock. Data ofhorizontal resolution generated by the signal processing unit 104 istransferred to each pixel. Assuming that the resolution obtained byspreading the original pixel sizes over the entire surface is equivalentto 4 k×4 k, the original horizontal pixel number is approximately 4000.In a case where the central view-field region is 40° with respect to ahorizontal FOV of 100°, the outermost periphery is m=4, and a pixel sizemagnification is fitted by a quadratic function, the horizontalresolution is 4000 ( 56/100)+2000×( 22/100)+1333×( 14/100)+1000×(8/100)=Approximately 2950 pixels.

Consequently, the horizontal pixel number is compressed to approximately73%.

The scanner unit 300 transfers video data of effective 2950 pixels+blackinsertion 1050 pixels=4000 pixels. FIG. 26 is an explanatory viewillustrating configuration examples of the DAC unit 301, the AMP unit302, and the selection unit 303. In FIG. 26, the viewing angle of 0degrees is centered, and only the left side is illustrated. That is,only 2000 pixels are illustrated in FIG. 26.

The scanner unit 300 outputs video data of 4000 pixels. The data isreceived, and horizontal direction data is output through the DAC unit301 and the AMP unit 302. The selection unit 303 selects any output fromthe 4000 output signals.

Similarly to the gate driver unit 102, the number of 4000 can beexpressed by 12 bits. The selection unit 303 includes 12 stages oftransistors, and selects analog data to be input to a signal line. Forexample, in a case where the control signal input to the selection unit303 of all lines is [000000000000], all the lines select 0th data, andthus all pixels are simultaneously driven by the same data. FIG. 27 isan explanatory view illustrating the operation of the selection unit 303in a case where the control signal is [000000000000].

Furthermore, in a case where a control signal incremented by one bitfrom [000000000000] to [111111111111] is input to the selection unit303, normal active matrix driving in which scanning is performed every 1H is performed. FIG. 28 is an explanatory view illustrating theoperation in a case where a control signal incremented by one bit isinput to the selection unit 303.

Note that, although, in the embodiment, a method of selecting an analogvalue, which is output after DAC, at the selection units 201 and 303 isadopted, the disclosure is not limited to such an example, and can beachieved by a method of selecting a digital value.

FIG. 29 is an explanatory view illustrating a configuration example ofthe display system according to the embodiment. In the example in FIG.29, a line memory unit 401 is provided in the front stage of the datadriver unit 103. A parallel-to-serial conversion unit 402 converts datastored in the line memory unit 401 from a parallel signal to a serialsignal, and outputs the data. The data that has been converted into aserial signal is transmitted from a flip-flop 403 to the data driverunit 103 bit by bit on the basis of control data from the signalprocessing unit 104.

The parallel-to-serial unit 402 switches ON/OFF of a clock on the basisof the control data for the horizontal resolution generated by thesignal processing unit 104. In a case where the flip-flop 403 is usedand a logic, in which the clock is turned ON in a case of a controlsignal of one and the clock is turned OFF in a case of a control signalof zero, is adopted, next data is transferred in a case of a controlsignal of one, and data output of the preceding stage is kept in a caseof zero. The flip-flop 403 transfers next data at the time when theclock is switched from low to high, that is, the clock is once turnedON.

FIG. 30 is an explanatory view illustrating input/output of image data.The upper stage illustrates the input/output of image data in a casewhere input and output correspond one-to-one to each other. The lowerstage illustrates the input/output of image data in a case where inputand output do not necessarily correspond one-to-one to each other.Normally, if data for seven pixels is input as in the upper stage inFIG. 30, data is output for seven pixels.

In contrast, in the embodiment, as illustrated in the lower stage inFIG. 30, seven pixels of original size are used. One pixel of four timesthe pixel size, one pixel of doubled pixel size, and one pixel of onetime the original pixel size are arranged and displayed. A controlsignal [1000101] is input to the seven pixels. That is, the same data istransferred to the pixels of i=7 to 4. The same data is transferred tothe pixels of i=3 to 2. The same data is transferred to the pixel ofi=1. As a result of data being transferred to each pixel in this way,the magnification m=4, 2, and 1 can be expressed.

FIGS. 31 and 32 are explanatory views illustrating the driving of eachof the gate driver unit 102 and the data driver unit 103. FIGS. 31 and32 illustrate the driving at the time when three vertically andhorizontally quadrupled pieces of data, three doubled pieces of data,and four one-time piece of data are displayed with respect to a panelwith vertical eight pixels and horizontal eight pixels in one example.The display system according to the embodiment can display an imagemagnified to any magnification in any region of the panel unit 101 bythe gate driver unit 102 and the data driver unit 103 driving in thisway.

Although, in the above description, a fixed magnification value m isdetermined, the disclosure is not limited to such an example. Forexample, a line-of-sight of a user may be detected, and verticalsynchronization may be performed in accordance with the detection resultof the line-of-sight. A value of magnification and the number of pixelsto be collected may be changed in a time direction.

Furthermore, the signal processing unit 104 may change the value ofmagnification and the number of pixels to be collected in the timedirection in accordance with the substance of content to be displayed.For example, if information of a region (attention region) desired to bedisplayed with high resolution to a user is given as metadata intocontent to be displayed, the signal processing unit 104 may display theregion in the original pixel size, and may determine magnification onthe basis of a look-up table and the like in the other region.

Of course, the signal processing unit 104 may determine a region to bedisplayed in the original pixel size and a region to be displayed in alow resolution by combining the above-described result of detecting aline-of-sight and the result of the detecting the attention region. As aresult, a plurality of regions to be displayed in the original pixelsize may be placed in a screen. The signal processing unit 104 mayperform signal processing in which a plurality of regions to bedisplayed in the original pixel size is displayed in the original pixelsize and the other region has resolution gradually lowered toward theouter periphery of the image.

Although, in the embodiment, display control of magnifying an image isperformed over a peripheral view-field region while using the samelook-up table in the horizontal and vertical directions, the disclosureis not limited to such an example. Different look-up tables may be usedin the horizontal and vertical directions. In this case, since humaneyes have a wider central view-field region in the horizontal directionthan that in the vertical direction, a look-up table, with which theresolution is higher in the horizontal direction than in the verticaldirection, that is, a region displayed in the original pixel size isextended, may be used.

Furthermore, although, in the embodiment, an image is displayed with aresolution reduced by magnifying the image in the peripheral view-fieldregion, the disclosure is not limited to such an example. A load at thetime of displaying the image may be reduced not by limiting pixels to bedisplayed in the peripheral view-field region, that is, displaying theimage to all pixels but by displaying the image while thinning outpixels.

Furthermore, although, in the embodiment, the method of freely changinga gate and data wiring reversibly by using a DAC has been described, thedisclosure is not limited to such an example. An image may be displayedat a resolution reduced by making a part for collecting data to bedisplayed for a gate and data with a metal mask and magnifying the imagefor the peripheral view-field region.

2. CONCLUSION

As described above, according to the embodiment of the disclosure, therecan be provided a display system capable of displaying a high-qualityimage while inhibiting a load at the time of displaying the image infront of a user by allowing a central part of a display to have highimage quality and enlarging and displaying pixels in a peripheral part.

The display system according to the embodiment of the disclosure canreduce the load at the time of displaying an image as compared to thatin the case where the image is displayed as it is for all pixels. Thedisplay system is particularly preferable to a small display system suchas a head mounted display.

Each step in the processing executed by each apparatus in thespecification does not necessarily need to be processed in a time seriesin the order described as a sequence diagram or a flowchart. Forexample, each step in the processing executed by each apparatus may beprocessed in an order different from the order described as a flowchart,or may be processed in parallel.

Furthermore, a computer program for causing hardware such as a CPU, aROM, and a RAM built in each apparatus to exhibit functions equivalentto the configuration of each apparatus described above can also becreated. Furthermore, a storage medium in which the computer program isstored can be provided. Furthermore, a series of processing can beperformed by hardware by configuring each functional block illustratedin the functional block diagram by hardware.

Although the preferred embodiment of the disclosure has been describedin detail above with reference to the accompanying drawings, thetechnical scope of the disclosure is not limited to such an example. Itis obvious that a person having ordinary skill in the art of thedisclosure can arrive at various alternations or modifications withinthe scope of the technical ideas set forth in the claims. Thesealternations or modifications are understood to naturally fall withinthe technical scope of the disclosure.

Furthermore, the effects described herein are merely illustrative orexemplary, and not limitative. That is, the technique according to thedisclosure may have other effects that are obvious to a skilled personfrom the description of the specification, together with or in place ofthe above-described effects.

Note that, the configurations as described below also fall within thetechnical scope of the disclosure.

(1)

A display control apparatus including a signal processing unit thatperforms signal processing in which a first mode and a second mode areswitchable at a first region in a screen and a region other than thefirst region in the screen, display being performed in the screen at afirst resolution in the first mode, display being performed in thescreen at a second resolution in the second mode.

(2)

The display control apparatus according to (1), in which the signalprocessing unit performs display while relatively reducing a resolutionin the second mode from a center of the screen toward an outer peripheryof the screen.

(3)

The display control apparatus according to (1), in which the signalprocessing unit determines the first region and the region other thanthe first region on the basis of a predetermined quadratic functionspecifying relation between a viewing angle from the center of thescreen and a display magnification.

(4)

The display control apparatus according to (3), in which the signalprocessing unit determines the first region and the region other thanthe first region by linearly approximating the quadratic function.

(5)

The display control apparatus according to (3) or (4), in which thesignal processing unit determines the first region and the region otherthan the first region by determining a size of a displayed region withrespect to a viewing angle from the center of the screen.

(6)

The display control apparatus according to any one of (3) to (5), inwhich the signal processing unit determines the first region and theregion other than the first region by determining a pixel number withrespect to a viewing angle from the center of the screen.

(7)

The display control apparatus according to (5) or (6), in which thesignal processing unit determines a display magnification with respectto each pixel of the screen.

(8)

The display control apparatus according to any one of (1) to (7), inwhich the signal processing unit determines the first region on thebasis of an attention region of content displayed in the screen.

(9)

The display control apparatus according to any one of (1) to (8), inwhich the signal processing unit determines the first region on thebasis of a result of detecting a line-of-sight of a user watching thescreen.

(10)

The display control apparatus according to any one of (1) to (9), inwhich the signal processing unit outputs a signal for driving a driverto the driver, the driver supplying a signal to a pixel of the screen.

(11)

The display control apparatus according to any one of (1) to (10), inwhich one piece of display information corresponds to one pixel of thescreen in the first resolution.

(12)

The display control apparatus according to any one of (1) to (11), inwhich the first resolution is higher than the second resolution.

(13)

A head mounted display including the display control apparatus accordingto any one of (1) to (12).

(14)

A display control method including a processor performing signalprocessing in which a first mode and a second mode are switchable at afirst region in a screen and a region other than the first region in thescreen, display being performed in the screen at a first resolution inthe first mode, display being performed in the screen at a secondresolution in the second mode.

(15)

A computer program causing a computer to perform signal processing inwhich a first mode and a second mode are switchable at a first region ina screen and a region other than the first region in the screen, displaybeing performed in the screen at a first resolution in the first mode,display being performed in the screen at a second resolution in thesecond mode.

REFERENCE SIGNS LIST

-   100 Pixel-   200 Scanner unit-   202 Buffer unit-   203 Output node

The invention claimed is:
 1. A display control apparatus, comprising: asignal processing unit configured to: determine a first count of pixelswith respect to a viewing angle from a center of a screen; change thefirst count of pixels to a second count of pixels based on metadata ofcontent to be displayed on the screen, wherein the metadata of thecontent includes information of an attention region associated with thecontent, and the attention region is a region to be displayed at a firstresolution; determine a first region and a second region on the screenbased on the second count of pixels, wherein the second region isdifferent from the first region; control, in a first mode, display ofthe content at the first region; and control, in a second mode, displayof the content at the second region, wherein in the first mode, thedisplay of the content is at the first resolution, and in the secondmode, the display of the content is at a second resolution lower thanthe first resolution.
 2. The display control apparatus according toclaim 1, wherein at a time of the display of the content in the secondmode, the signal processing unit is further configured to reduce thefirst resolution of the display of the content from the center of thescreen toward an outer periphery of the screen.
 3. The display controlapparatus according to claim 1, wherein the signal processing unit isfurther configured to determine the first region and the second regionbased on a specific quadratic function, and the specific quadraticfunction specifies a relation between the viewing angle from the centerof the screen and a display magnification.
 4. The display controlapparatus according to claim 3, wherein the signal processing unit isfurther configured to determine the first region and the second regionbased on a linear approximation of the specific quadratic function. 5.The display control apparatus according to claim 3, wherein the signalprocessing unit is further configured to: determine a size of a displayregion on the screen with respect to the viewing angle from the centerof the screen; and determine the first region and the second regionbased on the determined size of the display region.
 6. The displaycontrol apparatus according to claim 5, wherein the signal processingunit is further configured to determine the display magnification withrespect to each pixel of the screen.
 7. The display control apparatusaccording to claim 1, wherein the signal processing unit is furtherconfigured to determine the first region based on a user's line-of-sighttoward the screen.
 8. The display control apparatus according to claim1, wherein the signal processing unit is further configured to output afirst signal to a driver, and the driver supplies a second signal to apixel of the screen based on the first signal.
 9. The display controlapparatus according to claim 1, wherein one piece of display informationcorresponds to one pixel of the screen in the first resolution.
 10. Ahead mounted display, comprising: a display control apparatus thatincludes a signal processing unit configured to: determine a first countof pixels with respect to a viewing angle from a center of a screen;change the first count of pixels to a second count of pixels based onmetadata of content to be displayed on the screen, wherein the metadataof the content includes information of an attention region associatedwith the content, and the attention region is a region to be displayedat a first resolution; determine a first region and a second region onthe screen based on the second count of pixels, wherein the secondregion is different from the first region; control, in a first mode,display of the content at the first region; and control, in a secondmode, display of the content at the second region, wherein in the firstmode, the display of the content is at the first resolution, and in thesecond mode, the display of the content is at a second resolution lowerthan the first resolution.
 11. A display control method, comprising:determining, by a processor, a first count of pixels with respect to aviewing angle from a center of a screen; changing, by the processor, thefirst count of pixels to a second count of pixels based on metadata ofcontent to be displayed on the screen, wherein the metadata of thecontent includes information of an attention region associated with thecontent, and the attention region is a region to be displayed at a firstresolution; determining, by the processor, a first region and a secondregion on the screen based on the second count of pixels, wherein thesecond region is different from the first region; controlling, in afirst mode, display of the content at the first region; and controlling,in a second mode, display of the content at the second region, whereinin the first mode, the display of the content is at the firstresolution, and in the second mode, the display of the content is at asecond resolution lower than the first resolution.
 12. A non-transitorycomputer-readable medium having stored thereon computer-executableinstructions that, when executed by a processor, cause the processor toexecute operations, the operations comprising: determining a first countof pixels with respect to a viewing angle from a center of a screen;changing the first count of pixels to a second count of pixels based onmetadata of content to be displayed on the screen, wherein the metadataof the content includes information of an attention region associatedwith the content, and the attention region is a region to be displayedat a first resolution; determining a first region and a second region onthe screen based on the second count of pixels, wherein the secondregion is different from the first region; controlling, in a first mode,display of the content at the first region; and controlling, in a secondmode, display of the content at the second region, wherein in the firstmode, the display of the content is at the first resolution, and in thesecond mode, the display of the content is at a second resolution lowerthan the first resolution.